Text classification of non-equal length texts, should I pad left or right?
For any model that does not take a time series approach like an RNN does, the padding shouldn't make a difference.
I prefer padding right simply because there also might be text you need to cut-off. Then padding is more intuitive as you either cut-off a text if it's too long or pad a text when it's too short.
Either way, when a model is trained a certain way, it shouldn't make a difference so long the testing is also padded the way it was presented in training.